Merge PR #53070 into main

* refs/pull/53070/head:
	PendingReleaseNotes: add note about 'm' and 'M' periods
	doc/cephfs: add note about monthly scheduling and retention period
	qa: update minute period multiplier to m
	qa: change minute duration specifier from M to m
	mgr/snap_schedule: change minute duration specifier from M to m

Reviewed-by: Dhairya Parmar <dparmar@redhat.com>
Reviewed-by: Neeraj Pratap Singh <neesingh@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>